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2. 学习C ++
3. 嵌套的switch语句(nested switch statements)

嵌套的switch语句(nested switch statements)

可以将开关作为外部开关的语句序列的一部分。 即使内部和外部交换机的大小写常量包含公共值，也不会产生冲突。

C ++指定允许至少256级嵌套用于switch语句。

语法 (Syntax)

nested switch语句的语法如下 -

switch(ch1) {
   case 'A': 
      cout << "This A is part of outer switch";
      switch(ch2) {
         case 'A':
            cout << "This A is part of inner switch";
            break;
         case 'B': // ...
      }
      break;
   case 'B': // ...
}

例子 (Example)

#include <iostream>
using namespace std;
int main () {
   // local variable declaration:
   int a = 100;
   int b = 200;
   switch(a) {
      case 100: 
         cout << "This is part of outer switch" << endl;
         switch(b) {
            case 200:
               cout << "This is part of inner switch" << endl;
         }
   }
   cout << "Exact value of a is : " << a << endl;
   cout << "Exact value of b is : " << b << endl;
   return 0;
}

这会产生以下结果 -

This is part of outer switch
This is part of inner switch
Exact value of a is : 100
Exact value of b is : 200